The Polonovski–Potier Reaction of Berbine N-Oxides. Synthesis of 8-Hydroxymethyl and 8-Methylberbines

The Polonovski–Potier reaction of trans and cis berbines N-oxides was studied. The 8-cyano derivative obtained from trans N-oxides were used to synthesize 8-hydroxymethyl and 8-methyl berbines. This procedure was applied to the stereocontroled synthesis of (8R, 14S)-(−)-8-methylcanadine from (14S)-(−)-canadine.